Method of reclaiming electric lamps



Jan. 5, 1937. c. BIRDSEYE METHOD OF RECLAIMING ELECTRIC LAMPS Filed March 23, 1934 firvezrtor ctmwu Z514h7 bty 7 My affoiwgj Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE METHOD OF REClfillirlllflNG ELECTRIC Application March 23, 1934, Serial No. 717,019 13 Claims. (01. 176-7) -This invention relates to the reclaiming of burned-out electric lamps and consists in a novel and improved method of removing the burnedout mounts from the bulbs of such lamps and preparing the bulbs for the reception of new mounts.

In one aspect the invention is a further de-' velopment of andimprovement upon the commercial method of reclaiming electric lamps disclosed in U. S. Letters Patent No. 1,920,528, granted August 1, 1933, to Butler and Lane, and in accordance with which the neck of the burnedout bulb is severed on a line which is usually located above the-line of juncture between the bulb and the flare of the filament mount. In following the method of that patent, therefore, a small amount of material is lost from the end of the neck of the bulb at each severing operation. This is not usually objectionable unless the bulb is subjected torepeated reclaiming operations, but under those conditions the bulb may be eventually shortened and the capacity of its chamber consequently reduced. An object of the present invention is to make available a commercially practicable method whereby the reclaiming operation may be effected without loss of material from the bulb so that its original shape may be exactly reproduced, if desired, or.

surplus material provided to facilitate reshaping of the bulb and rescaling of a new mount therein.

In another aspect the invention consists in a novel method of removing the mount from a burned-out lamp in such manner as to leave a portion of the mount .united to the neck of the bulb and so provide material for replenishing the bulb in the reshaping operation. This desirable result is accomplished, as herein shown, by heating the hollow mount in a zone within or above 0 its line of juncture with the neck of the bulb to render it plastic or to sever it. The mount may thus be cut off while it remains in place within the contour of the bulb, or the plastic portion of the mount may be drawn outwardly until it protrudes more or less beyond the base of the bulb and then cut off in its protruding position. The exact location of the line of severance is of secondary importance only so long as it involves no waste of material from the bulb 0 neck. It may be closely adjacent to the original line of juncture between the bulb and the mount, or it may be at such a location as to leave a substantial rim of the material of the mount united to the walls of the neck; In either case, the bulb opening may be reshaped preparatory to receiving a new mount without loss of material and its original shape may thus be reproduced.

Where it is desired to draw a portion of the mount outwardly into a protruding position before severing it, this may be readily and conven- 5 iently accomplished by engaging the lead-in wires of the lamp and pulling them outwardly. Under such conditions, the unsoftened inner end of the mount in which the lead-in wires are imbedded acts to force ahead of it the walls which 10 have been rendered plastic and, in effect, to turn a portion of the mount inside out. When this step has been carried out, the cutting ofi operation may be conveniently effected at any desired distance from the original line of seal and 15 a rim of any desired width may be left united to the opening of the bulb neck.

While I have above outlined a preferred meth 0d of procedure, it is within the scope of the present invention to sever the mount in any manner which obviates wastage of the material of the bulb neck. For example, the mount might be severed by a rotary scratching tool operating upon a line or in a plane within the line of juncture between the mount and the neck of the bulb, or the mount may be severed by grinding or sand blasting the roll of the flare of the mount.

Where a grinding step is practiced, I have found it advantageous to heat the neck of the bulb preparatory to the cutting ofi step to avoid break- 30 age.

The nature and scope of my invention will be best understoodand appreciated from the following description of two of the many ways in which it may be put into practice, as illustrated in the 35 accompanying drawing, in which Fig. 1 is a view in side elevation, partly in section, of a burned-out bulb being subjected to the first step of my improved process;

Figs. 2, 3, and 4 are sectional views on a 40 slightly larger scale indicating progressive steps of the method;

Fig. 5 is a view in side elevation indicating the step of removing the severed mount;

Fig. 6 is a similar view, partly in section, indicating the step of shaping the bulb neck;

Fig. 7 is a fragmentary view illustrating an alternative method of severing the mount; and

Fig. 8 is a sectional view showing the condition of the bulb neck after the mount has been severed by the operation shown in Fig. 7.

The particular type of electric lamp selected herein for illustrating the novel method of my invention comprises a bulb l0 having an inwardly tapering neck 12, to the end of which is sealed 5 the curved flare I6 of a hollow mount I8. The line of seal I4 is indicated by a slightly thickened annular rib of glass which marks the juncture of the margin of the neck of the bulb with the flare of the mount I8. The mount terminates inside the bulb in a solid end portion 20, from which projects a supporting post 22 for the filament 24. Lead-in wires 26 pass inwardly through the mount I8 and. are sealed into the solid part thereof on their way to the filament. The mount contains a small exhaust tube or hollow stem 28 opening into the interior of the bulb through the solid portion 20 of the mount. In manufacturing the lamp, the bulb is exhausted through this stem and the stem is then sealed, after which a metallic cap is cemented or otherwise secured to the end of the bulb. The lamp above described is a well-known commercial article and may be treated advantageously by the novel method of my invention. However, the invention is not limited to this or to any other particular type of electric lamp but may be applied with suitable modifications to other forms of lamps and radio tubes.

The first step of the method illustrated in Figs. 1 to 6 consists in heating the mount I8 'within or, if the bulb be inverted, below the original line of seal I4 and in an annular zone. For this purpose, the lamp is rotated about a vertical axis while being subjected to the action of a flame from a burner 30 mounted obliquely above the lamp. The heating operation is continued until the material of the mount is reduced to a plastic condition or, if desired, it may be continued until the mount is actually severed in such heated zone. In either case, however, the outer portion of the flare I6 is left intact and it is not sufliciently softened to be rendered plastic in the immediate vicinity of the line of seal I4. During this operation the neck of the bulb remains undisturbed in shape, as does also the thickened rib including the original line of seal.

Having thoroughly softened the walls of the mount in an annular zone as abovedescribed, the lead-in wires 26 are immediately grasped by gripper jaws 32 and the softened mount is drawn outwardly by pulling on the lead-in wires as indicated in Figs. 2, 3 and 4. In this operation, the softened walls of the mount bulge slightly and roll outwardly, forming a protruding portion which extends outside the plane of the original end of the bulb while leaving the marginal portion of the flare intact and united to the neck of the bulb. In Fig. 2, this drawing onflowing step is shown as having been carried to a slight extent, and in Fig. 3 the mount is still further drawn outwardly, forming in process the fold vertex I9 in what was formerly the reentrant or inwardly-extending wall of the mount; When this operation has progressed to the desired point, as, for example, that shown in Fig. 4, the mount may be readily severed by a flame from a burner 34 directed against the outer wall of the protruding portion of the mount. The severing flame may be located wherever desired so long as by its action no material is removed from the neck of the bulb, that is, the mount may be severed closely adjacent to the original line of seal I4 or it may be severed at a substantial distance therefrom, as suggested in, Fig. 4.

Having once severed the mount, itmay be entirely removed from the bulb, as suggested in Fig. 5, by continued withdrawing of the gripper jaws 32. when this is'eflected, the neck of the bulb will have been provided with an upstanding collar or rim 2I which has been formed from the glass of the mount or of its flare.

After the mount has been removed from the bulb, the neck opening I2 and the attached collar or rim ZI may be again heated, as by the flame from burners 36 and 38, and reshaped by being rotated against a downwardly projecting spindle 40. This operation, as illustrated in Fig. 6, serves to mold the projecting rim portion 2| of the bulb outwardly to the desired extent, the extent illustrated bringing the rim substantially into alignment with the neck end of the bulb. When thus shaped, the bulb is ready to receive a new mount therein and have its rim portion 2I sealed to the flare of such mount in accordance with known practice.

It has been noted that the thickened rib denoting the original seal line is maintained intact during the steps of my novel method. The presence of this rib in the neck of the reclaimed lamp bulb is of advantage since it improves the holding or anchorage for the metallic cap to be subsequently secured to the neck by cement or otherwise.

As an example of other methods which may be used to sever the mount in the practicing of my invention, I have illustrated in Fig. 7 the severing operation as performed by grinding. Any suitable grinding medium or wheel may be used, and I have illustrated, for example, a grinding wheel 42 having a peripheral grinding surface 44. The end of the bulb, formed by the convex flare of the mount or by a portion of the mount which has been drawn outwardly to any desired extent, as suggested in Figs. 2-4, is placed against the surface 44 and slowly rotated while the grinding operation is proceeding. Such operation results in cutting through the end of the mount thereby freeing the mount from the bulb and leaving the end of the bulb open and a rim 46 projecting outwardly beyond the original seal line. The mount may thereafter be removed from the bulb and the reclaiming process proceeded with as before.

I have found that the grinding operation may be facilitated and fracturing of the glass reduced 1. A method of reclaiming electric lamps and adding material to the neck of the bulbs, characterized by the steps of heating the hollow mount of the lamp in a zone beyond its line of juncture with the neck of the bulb, pulling the heated portion of the mount outwardly in a manner extending the bulb length, and cutting off the mount in such a manner as to leave a rim portion thereof attached to the neck.

2. A method of reclaiming electric lamps, characterized by the steps of heating the hollow mount of the lamp to plastic condition by a. flame directed obliquely against its inner wall, pulling the heated mount outwardly, and cutting off the mount beyond its line of juncture with the neck of the bulb to leave an annular portion of the mount attached to the bulb.

3. A method of reclaiming electric lamps which consists in first heating to a plastic condition an annular zone in the mount, then pulling outwardly the lead-in wires to bring a portion of the mount into protruding condition, and finally severing the mount in its protruberant portion.

4. A method of reclaiming electric lamps characterized by the steps of heating to a plastic condition an annular zone in the mount beyond its line of juncture with the base, then turning the heated portion of the mount inside out by pulling upon the lead-in wires, severing the mount near its fold vertex, and reshaping the material remaining about the neck of the bulb.

5. A method of reclaiming electric lamps characterized bythe steps of heating by flame to a plastic condition an annular zone in the mount inwardly of the flare thereof, drawing outwardly the lead-in wires to cause the plastic walls of the mount to 'double on themselves and move outwardly until they protrude beyond the original line of juncture between the mount and bulb neck, then severing the mount as it thus protrudes, and subsequently reshaping the opening of the bulb neck to include the unsevered material of the mount.

6. A method of reclaiming electric lamps characterized by the steps of heating an annular zone in the mount to a plastic condition without substantially softening the material adjacent to the original line of juncture between-the mount and the bulb neck, drawing the plastic walls of the mount outwardly beyond said line of juncture, severing the mount in its protruding portion, and then reworking the material of the neck and the unsevered material of the mount preparatory to receiving a new mount.

'7. A method of reclaiming electric lamp bulbs, which consists in heating the hollow mount of a burned out lamp in a zone inside the line of juncture with the neck of the bulb, softening the mount and not the bulb, pulling the heated portion of the mount outwardly without disturbing the shape of the bulb neck, and severing the mount in such a manner as to add material of the mount to the neck of the bulb.

8. A method of reclaiming the bulbs of burned out electric lamps, which consists in heating the hollow mount of a lamp to render it plastic while the neck of the bulb remains substantially unsoftened, and then pulling the mount outwardly without disturbing the dimensions of the bulb neck until separation occurs between the mount and neck in such manner as to add material 0! the mount to the margin of the neck.

9. The method of reclaiming electric lamps, characterized by the steps of first warming and then grinding the outermost roll portion 01' the flare to sever the mount within the original line of juncture between the bulb and the mount, and removing the severed mount from the bulb leaving a rim of glass attached to the neck of the bulb outside said line of juncture.

10. The method of reclaiming electric lamps, characterized by the step of cutting oil the mount at such a location as to leave an annular rim of its material attached to the neck of the bulb outside the original line of seal between the bulb and mount while the neck and the bulb are maintained in their original relation in the lamp, and

thereafter heating and reshaping said annular rim to add it to the material of the bulb.

11. The method of reclaiming the bulbs oil. burned-out electric lamps, which consists in heating the mount within the annular thickened rib denoting the original line. of seal between the mount and the end of the neck of the bulb, extruding and cutting ofi the mount in the portion which has thus been heated leaving said rib intact with a rim of glass projecting therefrom, and then reshaping the neck of the bulb to include a cylindrical wall extending beyond said rib.

12. The method of reclaiming electric lamps oi the kind having a bulb, and a mount formed with a flare which is welded to the neck of the bulb and is reentrantly disposed within the neck, comprising the steps of heating the reentrant zone of the flare to a plastic condition without so heating the neck of the bulb, pulling the mount and the plastic flare outwardly so that the flare protrudes from the neck of the bulb, and severing the protruding flare.

13. Method of reclaiming electric lamps of the kind having a bulb and a mount formed with a flare which is welded to the neck of the bulb and is reentrantly disposed within the neck, comprising the steps of heating the reentrant zone of the flare to a plastic condition without so heating the neck of the bulb, pulling the mount and the plastic flare outwardly so that the flare protrudes from the neck of the bulb, and severing the protruding flare beyond its line of juncture with the neck of the bulb to leave a protruding rim of the flare attached to the neck.

CLARENCE BIRDSEYE. 

